How Safe is the Water Cooler - Prairie Water News by liuhongmeiyes


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By Richard Pasquill, The Manitoba                               water cooler is not                          sur
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                                                                                                 If yo            ww       a                100       sur    d
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                                                                safety of the water                                       ant        on
E     ach year, many people turn away
      from municipal tap water in
favour of a water coolers/dispensers
                                                                will be very much in
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                                                                                                                                  lynx our w
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                                                                                                                free     to        y
of bottled water. In most cases, the                              Bacteria are known to be          The              1-8 you b you ca
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thought behind the change is that                               able to grow and reproduce                                        -72 oning quest
                                                                at an extremely fast rate.
                                                                                                                    ash               27.        us
bottled water is “safer than tap water”                                                                            on      Priz
                                                                                                                           il 1, e will
                                                                Because it can take several days to a                  Apr
and “tastes better”.                                                                                                             200       be
   Unfortunately, there are some                                week to use a 5 gallon jug of water,                                 7.
major problems brewing across the                               the bacteria count in the water can
country with the water                                          become excessive. Unlike tap water,
                                                                                                                  • Prepare a
coolers/dispensers of bottled water.                            the bottled water does not contain
                                                                                                                    disinfectant solution by diluting
The problem is proper maintenance.                              any residual of chlorine to control
                                                                                                                    15 ml of household laundry
If the proper maintenance of the                                bacterial growth and therefore is very
                                                                                                                    bleach (5.25% sodium
                                                                susceptible to contamination.
                                                                                                                    hypochlorite) in 5 L of clean
                                                                  Health Canada recommends the
                                                                                                                    warm water.
         In This Issue                                          cooler/dispenser be cleaned and
                                                                sanitized EVERY TIME A                            • Disconnect the water cooler from
              Vol. 16 No. 2                                                                                         the electrical supply.
                                                                BOTTLE IS CHANGED. While
               Fall 2006                                        this recommendation may sound                     • Remove the empty water bottle
 How Safe is the                                                excessive, the need to follow these                 and completely drain the
 Water Cooler? . . . . . . . . . . . . . . . . . . 1            guidelines has been examined by                     remaining water through the
                                                                numerous engineers and related                      spigots.
 Disinfecting Water Wells with
 Chlorine . . . . . . . . . . . . . . . . . . . . . . . . . 2   companies and found to be sound. In               • Remove the”no-spill” guard and
                                                                general, people are the principal                   baffle (if applicable) taking care
 Constructed Wetlands                                           source for bacterial contamination of               not to break or damage the
 Successfully Treat                                             coolers. Once the outside of the
 Town Effluent . . . . . . . . . . . . . . . . . . 4                                                                components. Clean and wash
                                                                cooler or bottle is contaminated by a               these items in the dishwasher or
 Quality Farm Dugouts –                                         person’s hands, it is simple for the                kitchen sink.
 A report card . . . . . . . . . . . . . . . . . . . 5          bacteria to be carried into the water             • Using protective gloves, face
 Lakes Disappearing                                             within the cooler.                                  shield and clothing, fill the
 on the Prairies?                                                 The cleaning instructions as                      reservoir with the disinfectant
 An Aquatic Whodunnit                         ........6         outlined by Health Canada are fairly
                                                                simple and are as follows.                                                  cont’d page 2
Prairie Water News

cont’d from page 1                          • Reassemble the baffle and the        bottles in a clean, cool, dark place
                                              “no-spill” guard.                    away from chemicals, paints or other
                                            • Disinfect the top and outside of a   dangerous substances. Due to
     solution and scrub the interior of       new bottle of water and place the    possible bacterial growth, do not
     the reservoir with a clean long-         bottle into the cooler.              store water for more that 30 days
     handled, soft bristled brush.                                                 even if the bottle is unopened.
                                            • Run water through the spigots
  • Drain some of the disinfectant                                                   To ensure proper operation of the
                                              and reconnect the cooler to the
    solution through the spigots and                                               water cooler/dispenser, clean the
                                              electrical outlet.
    allow the solution to sit for at                                               cooling apparatus, fan, fins, drip tray,
                                            If you refill your own water jugs,     and general exterior of the unit on a
    least 2 minutes but not longer
                                          always disinfect the empty jug when      regular basis. Refer to your
    than 5 minutes (to be effective
                                          you change the bottle and clean the      operational manual for specific
    but to prevent corrosion).
                                          cooler. Add a 1/8 cup of disinfection    details and procedures.
  • Drain the disinfecting solution       solution to the jug, replace the top       By following the proper procedures
    from the reservoir through the        and swish the solution around the        for cleaning and disinfecting the
    spigots and dispose of it though      interior of the jug making sure to       cooler/dispenser on a regular basis, the
    the sanitary system.                  include the hollow handle. Do not        bottled water can remain as bacterial
  • Rinse the reservoir and spigots       empty the disinfectant from the jug      free and good tasting as hoped.
    thoroughly with clean tap or          until ready to refill.                     For further information, please
    bottled water 2 to 3 times to           When multiple bottles of water are     contact your Provincial Water
    remove traces of the disinfectant.    purchased at one time, store the full    Technologist or PFRA.

Disinfecting Water Wells with Chlorine
by Rachelle Ormond, Alberta               disinfect a well. Many people feel       higher chlorine dosage of 200 to 1000
Agriculture, Food and Rural               that just pouring some liquid chlorine   ppm and is only effective if an acid is
Development, and Bob Buchanan,            down the well with a small amount of     used to lower the pH of the treatment
Alberta Agriculture, Food and Rural       water and pumping it out is a            solution. Regular well disinfection
Development                               satisfactory well disinfection           will reduce the chances of needing to
W       ater well disinfection
        questions are among the most
common questions that water
                                             The terms ‘well disinfection’ and
                                          ‘shock chlorination’ are often
                                                                                   perform a much more costly shock
                                                                                   chlorination that is best done by an
                                                                                   experienced water well driller.
specialists, public health inspectors     incorrectly used interchangeably. In       This article focuses on well
and water well drillers receive from      fact, well disinfection involves a       disinfection and provides some of the
rural residents across the Canadian       much lower chlorine dosage than          latest information regarding proper
Prairies. Understanding well              shock chlorination. Well disinfection    well disinfection procedures. By
disinfection is complicated because       is intended to provide routine control   doing regular disinfection, you may
there may be considerable differences     of nuisance bacteria and correct         be able to save yourself from
in the information provided by            periodic contamination of a well by      requiring more costly and technically
different people. It seems everyone       pathogenic bacteria. It usually          difficult shock chlorination treatment.
has their own favorite recipe on how      involves chlorine dosages of 50 to
to cook the bugs in a well.               200 parts per million (ppm).             How Chlorine Works
  Some people believe that if a little       Shock chlorination is recommended       Disinfection is the treatment of
bit of chlorine does a good job, then a   to remediate biofouled wells, and to     water to inactivate, destroy, and/or
lot of chlorine will only do a better     control problems caused by high          remove pathogenic bacteria, viruses,
job. Some folks are adamant that only     levels of nuisance bacteria such as      protozoa, and parasites. This can be
granular chlorine and not liquid          iron or sulphate reducing bacteria.      accomplished by either physical or
chlorine bleach should be used to         Shock chlorination uses a much           chemical means. The most common

 2     ...dedicated to protecting and improving rural water supplies
                                                                                              Prairie Water News

chemical method is to use a strong
                                              Table 1. Effect of pH on Chlorine Effectiveness in Water
concentration of chlorine bleach.
   Chlorine is a very reactive                      Water pH             Biocidal Effectiveness     Oxidative Effectiveness
substance. When added to a well, it                     5.5                      100 %                         0%
first combines with inorganic                           8.0                          12 %                     88 %
compounds such as hydrogen                              9.0                          2%                       98 %
sulphide gas, ferrous iron and                         10.0                      <1%                        > 99 %
manganese. No disinfection occurs at
this stage. After the chlorine reacts       effectiveness of chlorine to kill           penetrate the biofilm and restore well
with these compounds, the remaining         bacteria is dramatically reduced. At a      production and water quality.
chlorine reacts with organic matter.        chlorine dosage of 1,000 ppm, the pH
This reaction helps to eliminate some       of a water/chlorine solution may be
                                                                                        Well Disinfection
bad tastes and odour, but there is little   over 10. This may be beneficial in          Methods
disinfection at this stage. If the          removing some plugging materials;              The two most common methods of
chlorine demand exerted by inorganic        however, the biocidal effectiveness         well disinfection are simple
and organic compounds has been met,         becomes less than 1% (see Table 1).         chlorination and bulk displacement
any excess chlorine will combine with       High dosages of chlorine are also           chlorination. Simple chlorination
nitrogen compounds (primarily               very corrosive and could be harmful         involves adding a small volume of
ammonia) to form chloramines.               to metal well casings, water piping,        chlorine solution into the top of the
   The formation of chloramines             and fittings over time.                     water well, followed by running a
results in long lasting disinfection,                                                   garden hose down the top of the well
produces minimal chlorine                   Scheduling Well                             to circulate the water and chlorine
taste/odour, and controls microbial         Disinfection                                solution through the water system.
growth. Chloramines, however, are             Water wells should be disinfected         This method can provide some
slow acting disinfectants and require       for preventative maintenance every 6        temporary benefit; but it is not
long contact times for effective            to 12 months to control the                 nearly as effective as the bulk
disinfection. If more chlorine is added     population of iron and sulphate-            displacement method.
to the water, the chloramines are           reducing bacteria. In addition, water          The bulk displacement method
destroyed and excess chlorine, known        wells should be disinfected at the          involves preparing a predetermined
as the free chlorine residual, forms        time of construction and completion,        volume of chlorine and water and
hypochlorous acid (HOCL). HOCL is           whenever the distribution system is         then siphoning or pumping this down
a potent, fast acting disinfectant.         opened for repairs or maintenance, or       the well. The chlorine solution
   The addition of more chlorine            when pumping equipment and water            displaces all the water in the well
may be beneficial for disinfection;         piping are removed for repair or            casing, screen/borehole and
however there is a point where              replacement. Disinfection should also       immediate aquifer. This results in a
excessive chlorine concentrations           occur when lab results indicate the         much more effective well disinfection
can cause more damage than                  presence of coliform bacteria,              treatment. Research has shown that
benefit. Recent research has shown          following contamination by flood            70% granular, 5.25% liquid and 12%
that low dosages of chlorine                water, or after any change in water         liquid chlorine solutions all work
(around 200 ppm) are most                   clarity, color, odour or taste.             effectively. The key is to ensure that
effective. Previously recommended             Well disinfection will not be             the chlorine dosage is calculated
dosages of 1000 ppm of chlorine             sufficient if biofouling has occurred.      correctly. Liquid chlorine solutions
are in fact less effective due to a         Chlorine cannot effectively penetrate       have the advantage of being less
change in water pH.                         the heavy layers of biofilm to reach        expensive and readily available.
   Liquid chlorine and granular             the bacteria and kill them. Wells that         For more information about water
chlorine are both extremely alkaline.       have not been maintained regularly          well disinfection, refer to Water
This results in an increase in pH           will likely require shock chlorination      Wells…That Last for Generations
when mixed with water. As the pH of         and may require hiring a well driller       publication or contact a water
the water/chlorine solution rises, the      to agitate and acidify the well to          specialist in your area.

                                       ...dedicated to protecting and improving rural water supplies                        3
Prairie Water News

Constructed Wetlands Successfully Treat
Town Effluent
By Richard Pasquill, The
Manitoba Water Services Board

T    hrough foresight and
     inventiveness, the town of
Roblin has shown that post
secondary treatment of waste
water with constructed wetlands
is possible and has many
advantages. The most important
advantage is reduced nutrient
loading of downstream water
bodies. While there is still some
reluctance, on the part of the
regulatory bodies within the
province, to promote or accept
post secondary treatment of town
effluent with the use of wetlands,
this project has more than
adequately shown the benefits of
constructed wetlands. As our
lakes and rivers become richer in
nutrients, treating waste water
with wetlands may become more
commonplace across the prairies.
   The town of Roblin, in western
Manitoba, like most small centres
that dot the prairie landscape,
relies on lagoons as part of the
town’s effluent treatment process.
Once the effluent reaches a
quality sufficient to meet the
environmental requirements for
disposal, most towns discharge
the secondary cells into local
streams or rivers. This is usually
done at times of high water flow
to dilute the waste. However,
since 1979, Roblin has utilized all
of the liquid processed through its
lagoon system to irrigate cropland
adjacent to the lagoons.              irrigation system. This prompted the    result of the investigation, in 1998/99
   With the wetter weather            town to investigate a number of other   the town elected to build a 40 acre
encountered in the 1990s, too much    alternate disposal methods that might   wetland and an adjacent 15-20 acre
liquid was being produced to be       be incorporated into their overall
properly disposed of through the      effluent management scheme. As a                                 cont’d page 5

 4    ...dedicated to protecting and improving rural water supplies
                                                                                         Prairie Water News

hybrid poplar plantation for post        levels within the cells are maintained    from accumulating in the liquid and
secondary treatment of a portion of      at an optimum level of 30 cm (12          causing problems for the plants, a
the effluent.                            inches). Due to the shallow nature of     slow summer discharge has been
  Constructed wetlands are marshes       the flow in the wetlands, the area        undertaken from the last cell. Tests
that have been designed to treat waste   covered, and the large mass of plants     that have been carried out to this
water. Often they are built on sites     present, much of the liquid is lost to    point show that nearly all the
that were not previously wetlands and    evaporation and evapotranspiration.       nitrogen and phosphorous that was
are composed of a series of cells           While it took some time for the        carried over from the lagoon
through which the waste flows. As        establishment of the plants, growth       treatment was removed as the effluent
the liquid passes through the various    has now exceeded expectations with        passed through the first few cells of
cells, a natural purification process    the cattails exceeding 6-8 feet in        the wetland. Since its development,
takes place as bacteria break down       height with very dense growth             wildlife has proliferated throughout
organic matter. In addition, the         throughout the various cells. The         the wetland with a wide variety of
floating and rooted plants remove        quality of the effluent has improved      birds, frogs, and other wetland
plant nutrients such as nitrogen and     drastically as it slowly moves from       creatures migrating to the area.
phosphates from the liquid, further      cell to cell of the wetlands and plants      For further information, please
improving the water quality.             take up nutrients. By the time the        contact the Town of Roblin or The
Constructed wetlands are normally        liquid has passed through all the         Manitoba Water Services Board
seeded down to a variety of reed,        cells, it easily meets the very
sedge, rush and other marsh grass        stringent discharge requirements laid
plants. In order to properly optimize    down by Manitoba Environment. In
plant growth and longevity, the liquid   order to keep the mineral content

Quality Farm Dugouts – A report card
I  n 2002, Prairie Water News
   released a publication called
‘Quality Farm Dugouts’. The book is
                                         majority of respondents were mixed
                                         livestock/cropping farmers and
                                         livestock producers. Watering
                                                                                   appropriate. The sections of the book
                                                                                   that people reported as being most
                                                                                   useful included the modules about
a technical manual intended to           livestock was the most important use      operating systems, water quality,
provide readers with the latest          of dugout water for most respondents.     water treatment, and design and
research information about improving     Other important uses were lawn and        construction. Sections containing
both the quantity and quality of         garden irrigation and spray mixing.       more general information and the
dugout water. ‘Quality Farm Dugouts’     Based on the reported needs of these      schedules/forms were regarded as
has been distributed at no cost to the   dugout owners, future editions of this    less valuable.
public for the past four years.          manual will include sections on best        ‘Quality Farm Dugouts’ is available
   An evaluation of the manual was       management practices and/or               in hardcopy from any of the Prairie
undertaken through a survey to assess    operating guidelines for livestock        Water News partner agencies. It is
the usefulness of the book to its        watering systems, backflow                also available on line at:
readers. A questionnaire was             prevention devices, and water     $depar
administered to a sample of people       distribution/conservation with respect      tment/deptdocs.nsf/all/eng4696
who requested the manual.                to lawn/garden watering.
   The results indicate very clearly        In general, the publication was          We are always eager to hear from
that the audience for ‘Quality Farm      evaluated very favourably. People         our readers. Any comments or
Dugouts’ is the farm population who      reported being satisfied with the         criticisms you may have about
either already own dugouts and have      organization and layout of the book       ‘Quality Farm Dugouts’ are welcome.
existing water quality problems or are   and that the level of technical
intending to build a new dugout. The     complexity and detail was

                                    ...dedicated to protecting and improving rural water supplies                    5
Prairie Water News

Lakes Disappearing on the Prairies?
An Aquatic Whodunnit
Reprinted with permission from            resources to future changes – and can    rarely if ever overflows through an
EnviroZine, Environment Canada.           develop plans and strategies to offset   outlet. Water level records of closed-
[Aussi disponible en français]            impacts.                                 basin lakes can therefore serve as
                                            Garth van der Kamp, Marlene            long-term indicators of hydrological

P   rairie residents often lament their
    shrinking and disappearing lakes,
remembering a shoreline now
                                          Evans, and Dwayne Keir at the
                                          National Water Research Institute of
                                          Environment Canada are studying
                                                                                     With the support of the Prairie
                                                                                   Adaptation Research Cooperative
hundreds of metres away from the          seventeen lakes across the Canadian      (PARC), the researchers analyzed
beaches where they paddled as             Prairies to get a clearer picture of     water level records from several
                                                                                   sources including the Water Survey
                                                                                   of Canada’s Hydat database, the
                                                                                   Saskatchewan Watershed Authority,
                                                                                   Alberta Environment and historic
                                                                                   aerial photographs. They also
                                                                                   interviewed local communities to get
                                                                                   more information on past conditions.
                                                                                      Their data for closed-basin lakes
                                                                                   across the prairies show a general
                                                                                   trend of decreasing water levels
                                                                                   throughout the twentieth century,
                                                                                   with the decrease ranging from 4 to
                                                                                   10 meters. Manito Lake in western
                                                                                   Saskatchewan, for example, has
                                                                                   dropped 7 meters since 1920. The
                                                                                   water level change at Manito Lake
Manito Lake, 2005                                                                  has altered the shoreline to the point
                                                                                   where Sugar Loaf “Island” is now a

children. Speculation about a             their history over
dwindling water supply appears            the last 100 years
frequently in the media, with             and, ultimately, to
shrinking glaciers and a warming          find explanations
climate cast as villains that threaten    for a disappearing
prairie agriculture, the economy, and     natural resource.
a sustainable supply of freshwater for      They are focusing
public consumption.                       on closed- basin
  But is there really less water on the   lakes. Unlike
Prairies than there used to be? If so,    through-flow lakes
how much less? And what does that         where the higher
mean for the future? Water managers       the lake level rises,
and decision-makers need a better         the faster the water
grasp on what changes have actually       flows out through
occurred over time so they can assess     an outlet creek, a
the vulnerability of prairie water        closed basin lake       Lake water level change.

 6    ...dedicated to protecting and improving rural water supplies
                                                                                        Prairie Water News

                                                                                                 however, perhaps there
                                                                                                 was more snow and rain
                                                                                                 over 100 years ago,
                                                                                                 before anyone was
                                                                                                 measuring precipitation,
                                                                                                 and the lakes are still
                                                                                                 coming down from that
                                                                                                 high. The prairie climate
                                                                                                 is getting warmer.
                                                                                                 Winters are shorter now
                                                                                                 by a month compared to
Manito Lake in 2005 compared to photo taken in 1922 by D.S. Graham.                              50 years ago and so
                                                                                                 summers are a month
                                                                                                 longer. Is the resulting
peninsula! Little Fish Lake in Alberta   of lake recreational areas hits local    increased evaporation enough to
had 5 meters of water in 1975, but       residents and the economy; fish and      account for declining lake levels?
was completely dry in May of 2005.       wildlife habitat is disrupted and the      All these explanations have a
Kenosee Lake in south-eastern            aquatic ecosystem altered; and the       degree of truth in them and the
Saskatchewan is down by 6 meters         available water supply for public use    challenge now is for researchers to
since the 1920s.                         is diminished.                           work out how important each one is.
  The water input to the lakes,             Theories abound as to why lake        The research team will continue its
whether by runoff from the watershed     levels are going down. Perhaps it is     work investigating long-term records
or by precipitation on the lake, has     because dams upstream are                and present day conditions to find the
obviously been less than the loss by     impounding the water and not letting     answers – information that will help
evaporation through most of the last     it through to the lake? Perhaps          predict what the future may hold for
100 years. There have been               changes in agricultural practices such   prairie water resources and assist
temporary increases of water level,      as continuous cropping and minimum       policy and decision makers with
notably during the high snowfall         tillage are decreasing runoff? There     plans to meet changes.
years of the mid-1950s, the mid          are lots of beavers now in most            For more information contact
1970s and the late 1990s, but then       watersheds and perhaps they are          Environment Canada on the web at:
normal years return and water levels     doing the damage by trapping water
continue on downward.                    behind their dams.
                                            Or is it climate change?                The original article can be found at:
Why is it happening?                     Environment Canada records do not
  For these and many other lakes, the    indicate any clear change in             ssues/63/print_version_e.cfm
impact has been profound. The loss       precipitation since about 1900;

  • Data for closed-basin lakes across thecentury. show a general trend of decreasing
    water levels throughout the twentieth

  • Manito Lake in western Saskatchewan has dropped 7 meters since 1920.
  • Littleof 2005. in Alberta had 5 meters of water in 1975, but was completely dry in
           Fish Lake

  • Kenosee Lake in south-eastern Saskatchewan is down by 6 m since the 1920s.
                                    ...dedicated to protecting and improving rural water supplies                      7
Prairie Water News

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                                                                     If you would like to comment on articles in Prairie Water
    Clint Hilliard, AAFC-PFRA, Saskatoon, SK                         News or you have suggestions for topics that you would
    Sharon Reedyk, AAFC-PFRA, Edmonton, AB                           like to see addressed in the future, please send your ideas to:
    Richard Pasquill, Manitoba Water Services Board,                 Charlene Hudym, Saskatchewan Research Council, 125-15
    Brandon, MB
                                                                     Innovation Boulevard, Saskatoon, SK S7N 2X8, Tel: (306)
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    Saskatoon, SK                                                    endorsement by the authors, by the agencies, or by Prairie
                                                                     Water News of any of the products or services mentioned
    Managing Editors: Clint Hilliard, Sharon Reedyk                  herein.
    Contributing Editor: Charlene Hudym

                Fisheries and Oceans   Pêches et Océans
                Canada                 Canada

                                                              AGRICULTURE, FOOD AND
                                                                RURAL DEVELOPMENT
                                                           Engineering Services

8      ...dedicated to protecting and improving rural water supplies

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